Rechargeable metal hydride (MH) electrochemical cells are employed in numerous applications such as portable computers, phones, industrial applications, aerospace applications and electric vehicles.
The negative electrode (anode) of a metal hydride electrochemical cell may comprise an AB5, AB2, A2B7-type, Ti—Ni-based, Mg—Ni-based, BCC or Zr—Ni-based metal hydride alloy. The metal alloys are hydrogen storage alloys. Conventional AB5 and A2B7 alloys have capacities of from about 320 to about 360 mAh/g and are of relatively high weight. Desired are rechargeable electrochemical cells having lighter weight, higher capacity and higher gravimetric energy density.
It has been found that a negative electrode comprising a hydrogen storage material based on one or more group IV elements is highly effective as a hydrogen charge/discharge component in an electrochemical cell. The hydrogen storage material is for example based on silicon and/or carbon.